Circuit Description

Toothed wheel generates a voltage pulse as it moves past sensor. EBCM uses these pulses to determine wheel speed. The amount of voltage generated in each pulse depends on air gap between sensor and toothed wheel and wheel speed. EBCM uses wheel speed sensor signal to calculate vehicle reference speeds and individual speed, acceleration and slip values for each wheel. These values are used to determine when anti-lock control is needed.

Code 22 will be set if improper speed signals are generated by toothed ring sensor. Some causes are: incorrect number of teeth on sensor ring, sensor rings covered with dirt, grease or metallic particles, or damaged toothed sensor ring.

Code 22 may be set if mini-spare tire has been used or tire sizes on vehicle differ from each other.

Fig 1: Code 22: Ckt Diag. (Brougham, Eldorado, Seville)

Courtesy of GENERAL MOTORS CORP.

Fig 2: Code 22: Ckt Diag. (Reatta, Riviera, Toronado, Trofeo)

Courtesy of GENERAL MOTORS CORP.

Fig 3: Code 22: Diagnostic Flow Chart.

Courtesy of GENERAL MOTORS CORP.